"Usually of high natural fertility, they tend to accumulate organic matter readily and are of a ‘light’ nature (low bulk density) that is easily tilled. These soils generally have a high productivity potential."

"Adding just a small percentage of basaltic volcanic ash to forest soil triggered explosive plant growth in Coleus (Plectranthus scutellarioides) and a dramatic restructuring of the soil microbiome. At around three percent ash, it’s as if the whole soil ecosystem flips a switch. The plants grow taller with more aboveground biomass, reproduce more, and the microbial community in the soil reorganizes itself into a new, apparently more fertile system."

"Volcanic ash is a multi-nutrient mineral fertilizer whose catalytic mechanism of action, replenishing trace metals necessary to soil bacterial enzymes for the efficient biogeochemical cycling of key elements such as N, C, P, and S, ensures the use of relatively small amounts to fertilize large soil surfaces."

"As a result, Andisols have andic properties — unique chemical and physical properties that include high water-holding capacity and the ability to 'fix' (and make unavailable to plants) large quantities of phosphorus."

"Because they are generally quite young, andisols typically are very fertile except in cases where phosphorus is easily fixed (this sometimes occurs in the tropics). They can usually support intensive cropping, with areas used for wet rice in Java supporting some of the densest populations in the world."

"Andisols are common as the native tropical rainforest land area, and are utilized for productive agricultural soil, particularly for horticultural crops, tea plantations, and coffee plantations."

"Results showed that Andisols has the highest mean water storage capacity, followed by Entisols and Inceptisols which have loamy texture."

"Volcanic soils support crops such as rice fields in Indonesia, the Philippines, and Japan, sugar cane in Hawaii and Central America, and vineyards in Italy."

"With almost 40 million Indonesians relying on the agriculture industry to earn a living, the country’s volcanic regions feature some of the world’s most fertile soil. The earth is enriched with volcanic ash abundant in plant-boosting minerals like magnesium, silica and potassium."

"Volcanic soils support crops such as rice fields in Indonesia, the Philippines, and Japan, sugar cane in Hawaii and Central America, and vineyards in Italy."

"The steep-sided, cone-shaped Mount Merapi volcano is both boon and curse to the people of Indonesia. Volcanic ash from its frequent eruptions makes the soil fertile enough to support a large population. It is also one of Indonesia’s most active volcanoes, posing a constant threat to tens of thousands of people who live in its shadow."

"Jenni Barclay, a volcanologist at the University of East Anglia, explained that the question of why people live near volcanoes could just as easily be asked of city dwellers. People have extended families, friends, jobs, and a sense of belonging to their communities there, so moving away isn’t always an easy solution."

"With over 1,100 inhabitants per square kilometer, its population density is one of the highest in the world."